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This paper gives an overview on different antenna frontends for radar applications. Some properties of the showed systems are explained in more detail to present different ways to fulfill special system requirements. For example, the following system functionalities of different frontends are analyzed: ▪ radiation pattern synthesis ▪ sidelobe level ▪ first sidelobe reduction ▪ phase center synthesis...
Optical antennas are the counterparts of conventional radio frequency and microwave antennas for frequencies in the visible regime (-500 THz) [1]. They localize optical fields to sub-diffraction-limited volumes, enhance and redirect the excitation and emission of quantum emitters [2] as well as modify their spectra. They open up exciting opportunities in a wide range of fields including nonlinear...
Indoor Radar Cross Section (RCS) measurement is an important issue when the dimensions oí the anechoic chamber are not very large compared with the wavelength. Basically, the efficiency oí the chamber absorbing materials, that cover the inner surface, strongly decreases for low frequencies. In the V/UHF band, the measurement antennas usually consist of big horns. The trouble is that their directivity...
This paper presents the idea to develop a software framework in order to allow the integration of efficient UPC fast solvers with the method of moments kernels of other groups. This work should lead to a future open-source software project to integrates modules developed by different University groups expert either in accurate computation of Integral Equations Green's functions or in developing Fast...
We present a miniature fiber-optic magnetic field sensor that is capable of detecting the amplitude and phase of the measured field in the frequency range from 0.1–6 GHz. It is also capable of capturing the full time domain (base-band) signal information of modern communication signals. The sensor is based on a versatile optical platform to which various antenna types and amplifier stages may be connected...
An internal broadband IFA antenna for mobile is proposed. The designed internal antenna consists of L-shaped zeroth order resonator and folded first order Inverted-F element and has a comparatively small volume of 45 mm × 10 mm × 1 mm. The proposed antenna can achieve the wide bandwidth for GSM band.
The paper describes development of a millimetre-wave imaging system using multi-element aperture filling techniques [1]. Such imaging systems are increasingly demonstrated for security applications and in particular standoff imaging of persons and bonding flaw and defect detection [2]. The major impact of the imaging system presented here is the multi-element architecture in bi-static operational...
A Fast Physical Optics technique is presented for computing the RCS of 2D geometries described in terms of Rational Bezier curves. The algorithm is based on the path deformation technique. The exact integration path is computed analytically, therefore, the highly oscillatory PO integral is transformed into a slowly varying integral with exact accuracy.
A novel textile array antenna with special structure at 1.54GHz is introduced. The patch, the substrate and the ground are woven together as a unity. Measured results are compared with the simulated, showing the usefulness of new generation of textile antenna.
Bandpass and bandstop spatial filters based on the dielectric-rod EBG structures are proposed and validated for the frequency range from 18 to 25 GHz. The obtained experimental results are well consistent with the theoretical predictions. The exploited mechanism utilizes, in particular, anisotropic-like dispersion, which can occur in the conventional EBG structures made of isotropic materials.
In this paper a summary is presented of the practical limitations, both electrical and physical, of designing antennas for body-worn and man-portable applications.
The following paper describes the microwave imager/sounder MTVZA-GY for spacecraft "Meteor-M". The spacecraft has been launched On September 17, 2009. MTVZA-GY instrument will be used as the meteorological imaging/sounding system for remote sensing of ocean and land surface, as well as, for measuring global atmospheric temperature and water vapor profiles.
There is a need for novel diagnostic and treatment systems to overcome the limitations with todays modalities. Microwave and THz based system has the potential to become both sensitive and specific in several applications. In this paper we discuss several applications that are currently being developed at the Chalmers University of Technology.
Hardware acceleration equipment has pushed the limits for EM FDTD simulations. The capability to resolve structures in high detail has created a need for more accurate material models. The presented approach can treat any combination of the linear Drude, Debye and Lorentz models and the nonlinear Kerr- and Raman-effects. It is also possible to predict stability limits for any combination thereof....
For real-world usage, EMC problems at PCB level are massive and extremely complicated. Thus, EMC engineers generally solve these problems by following some design guidelines [1] and confirm the performance of their solutions directly with measurement and without simulations. Therefore, these solutions always need very rich practical experiences. Alternatively, numerical simulations can be helpful...
We report on the possibility of controlling the radiation pattern of a quasi-point source antenna with a high directivity by means of artificial metamaterial-based cloaks. The demonstration of high directivity via the engineering of core effective parameters, with performances comparable to those obtained by conventional techniques such as parabolic mirrors, is carried out numerically by means of...
Introduction and main concepts: An increasing interest in passive surveillance systems can be observed in last period. The key idea, which is also common to other non-radar applications, is to conveniently exploit opportunity signals, as analogue FM transmitters or Digital Video Broadcasters to detect and/or tracking targets [1–3].
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